That's strange. I don't have any problems with master server. Have you tried reinstalling LFS? Furthermore, the fact that you were able to write here confirms that the master server is online?
Dumb question, did you download a recent LFS version? (like not a 3 years old one xD)
Your internet browser reaching the forum does not imply that the game is able to contact the master server. There are many diferent protocols involved in those two connections
And the master server could be a program running in the background, that could crash despite the website keeps working fine.
i would hope that the master server just runs over port 80 as well because otherwise that would cause lots of unnecessary headaches for people. is there no other way to activate?